Wrench



Feb. 17; 1925.

L. W. ROBINSON WRENCH Wm ,3 w-mm 0% @W v 2/ m ZW Filed Dec. 5. 1923 Patented Feb. 17, 1925.

UNITED STATES LAWRENCE w. ROBINSON, or CHICAGO, ILLIivoIs.

WRENCH.

Application filed December 3, 1923.

To all whom it may con-Gem: v

Be it known that I, LAWRENCE W. ROBIN- soN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in a s Vrench, of which the following is, a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates to improvements in gripping tools and more particularly to an improved wrench for grasping a pipe, rod,

the head of a bolt, or a nut to hold or turn same, or for use wherever else adaptable.

The primary object of the invention is the provision of a tool with which an exceedingly powerful gripping force may be secured with a minimum of effort, and in a minimum of space and which can be applied to the object to be grasped with a minimum of application movement and without requiring access to the jaws of the tool themselves for setting them for the gripping action as it is now necessary in the ordinary Stillson type wrench.

Another object is the provision of a tool which will impart a powerful gripping force without distorting the object gripped as for example where the object is, of hollow or tubular formation and which may, when applied, be removed from the work or object, grasped with a minimum of effort and with a minimum of separating movement of the jaws.

' Another object is to minimize or eliminate the. tendency to force the object from the jaws in the gripping action of the awe and the provision of a tool the jaws of which may be separated and closed by a relative pivoting or fulcruming therebetween or by relative motion of translation. This increases the capacity of the tool and I provide for locking the jaws against pivotal action so that they may be separated or closed and applied to or removed from the work by relative motion of translation only where desired. 2 j e 1 Another object is the provision of a tool of this sort which may be used for cutting wire and the like when desired.

In accordance with the teaching of my invention I fulcrum or pivot the jaws or jaw carrying handles of the tool together at a point outwardly along the handles and in Serial no. 678,189.

substantially lateral alignment with the work or object gripping portions of the jaws. or in substantially a plane throughthe gripping portions of the jaws and substantially; parallel with the closing movement of the handles of the tool.

This permits a minimum angle between the jaws when they are swung wide open for gripping large objects and reduces the tendency to force the work' from the jaws in the gripping action, to a minimum. It also provides an exceedingly powerful lever age. The relatively movable jaw, considering one jaw relatively movable and the other relatively stationary, moves parallel to as well as toward the gripping face of they other jaw in the gripping action. The result is that the closing force of the jaws is not only a function of the handle lengths to the distance of the movable jaw from the pivot or fulcrum but is also a function of the relative movement of the jaw toward the other to the relative movement parallel to the other jaw. In addition the tendency to open the other jaw by the closing force of the relatively movable jaw is minimized.

To acquaint those skilled in the art with the nature and scope of the invention I will now describe a particular embodiment of the invention in connection with the accompanying drawings in which;

Figure l is aside elevat-ional view of a tool embodying the invention;

Fig. 2 is an edge view of the left hand edge of the tool shown in Fig. 1;

Fig. 3 is a fragmentary detail section on line 3-3 of Fig. 1;

Fig. 4L is a fragmentary detail section on line 4.4 of Fig. I;

Fig. 5 is a fragmentary detail section on line 5-5 of Fig. 1; and

Fig. 6 is a. detail section on line 6+6 of Fig.1. r

The tool shown in the drawings comprises a pair of arms 5 and 6 having handle portions 7 and 8. Arm 5 is metal stamped into substantially U-fo-rmation and bifurcated from its upper end down to a point below the crossing of the arms by a central longitudinal slot 9. Arm 6 has at its upper end a head 10 having an upper edge 11 finished obliquely, preferably at about 30 degrees to a plane centrally and longit'udiiially through arm 6.

Arm 6 extends through slot 9 dividing the upper end of arm 5 and crosses said arm 5 at 12. At one end of edge 11 head 10 has an outwardly projecting integral lug 13 and the extending portions of arm 5 lying on opposite sides of head 10 are pivoted or fulcrumed to projecting lug 13 by a pin 14. This pivots or fulcrums arm 5 on head 10 outwardly beyond edge 11.

Riveted, welded or otherwise secured be-V tween the upper divided ends of arm 5 is a block 15 having a serrated face 16 constituting one of the gripping jaws of the tool. Theserrations in face 16 may extend across the adjacent edges of the divided ends of arm 5or said edges may terminate short of the serrated gripping face. I

Mounted on head 10 and adjustable toward and away from jaw 16 by a motion of translation parallel to edge 11 is a second jaw 17 having a serrated gripping face 18 substantially normal to edge 11. Head 10 has a groove 20 having an enlarged inner end 25 and the inner end of jaw 17 engages and is guided in groove 20 along edge 11. For adjusting jaw 16 by a motion of translation the lower edge of the jaw has teeth 22 forming a rack which engages with an adjusting worm or screw nut 24 mounted in an opening 25 in head 10. Adjusting worm or screw nut 24 is carried by a pin 26 journaled at its inner end at 27 in head 10 and having threaded engagement at 28 with worm or nut 24. The outer end of pin 26 extends through an opening 30 in head 10 and on said outer end is an adjusting wheel 31 having a knurled periphery, for example, and an integral hub 32 which extends through opening 30 and at its inner end has a projecting prong or pin 33 engaging in nut 24 and locking the nut and adjusting wheel for rotation together. A nut 34 threaded on the outer end of pin 26 looks wheel 31 in place thereon. The threaded or screw portion of worm or nut 24 is preferably left handed and wheel 31 permits convenient manipulation of the worm and adjustment of jaw 17 from either side of the tool.

The gripping face of jaw 16 lies substantially parallel with the gripping face of jaw 17 throughout substantially the entire range of gripping action of the jaws. The angle of the gripping faces of these jaws is minimized even when arms 5 and 6 are swung about pivot 14 to wide open position. Pivot or fulcrum 14 lies in substantially a plane parallel to the movement of arms 5 and 6 and through the gripping portions of jaws 16 and 17. It lies substantially normal to the face of jaw 16 so that in closing this aw about pivot 14 the jaw will, instead of moving directly toward jaw 17, move parallel to and toward said jaw. The result is a rolling engagement with the object grasped and by reason of making the gripping action a function of the movement to ward and parallel to jaw 18 an exceedingly powerful gripping force is applied.

The gripping faces of the jaws remain substantially parallel throughout substantially the entire gripping action. The angle produced between said jaws in closing is minimized so that there will be no tendency in gripping the object to force the same out from the or to crush or force the object in toward edge 11 with an over-riding or further closing of the outer ends of the jaws which makes removal of the tool from the work diiiicult and inconvenient.

In use jaw 17 is adjusted by wheel 31 to substantially the jaw opening desired. The jaws are tnen separated slightly by pivotal movement about pivot 14 to receive the work and jaw 16 is then swung into gripping engagement with the work by pivotal movement of arm 6 about pivot 14. Upon setting jaw 16 up into engagement with the work it may even be released and turning of the tool as a unit to turn the nut or bolt, for example, or grasping and turning the tool with handle 8 alone will force both aws into firm gripping engagement with the work. In operation, of course, both handles are usually grasped together, but I point out the foregoing to illustrate that handle 7 may serve simply for the purpose of setting the jaws into gripping engagement with the work. Such setting is necessary and in a Stillson type wrench, access to the jaws for that purpose is required. The space into which the tool jaws must be arranged is frequently limited and in such case access to the jaws for the purpose of setting them is a considerable disadvantage.

1t should'be noted that the projection of jaws 16 and 17' from edge 11 is not great and this along with the arrangement of the jaws to operate at an angle to a central plane longitudinally through arm 8 permits access to work in limited spaces. Due to the fact that there is no'over-riding of the outer ends of the jaws, opening or releasing movement thereof is minimized and removal of the tool from the work is facilitated.

The end of arm 7 carries a pivoted link or bail 40 adapted to fit over and hook on the end of arm 8 to hold or look the arms against pivotal movement in which case opening and closing of the jaws may be by adjustment of jaw 17 only.

A cutter 42 having a knife edge 43 is mounted in arm 8 by an integral threaded stud or pin 44 and has a shoulder 45 cooperating with one edge of U-shaped handle 7 to limit closing of the jaws about pivot 14. When it is desired to cut wire or the like with the tool, cutter 42 is removed from arm 6 and secured upon jaw 16 with its pin or post in a socket 46. Thereupon closing of the jaws moves cutter edge 43 toward jaw 18 to cut wire or any other stock that may be arranged therebetween.

Various deviations and changes, such as positioning of pivot 14 still further outwardly and changing the jaw faces and adj usting nut as well as the particular construc tion of arms 5 and 6 are contemplated within the spirit and scope of the appended claims.

I claim:

1. In a device of the class described, an arm having a head, a jaw adjustable on said head obliquely to said arm, a lug projecting outwardly from said head, a second arm pivoted on said projecting lug in substantially the line of adjustment of said jaw, and a jaw on said second arm for cooperation with said first jaw.

2. In a device of the class described, an arm substantially U-shaped in cross-section and bifurcated at its outer end, a second arm projecting through the bifurcation of said first arm and crossing said arm, said second arm having a head with a lug pnojecting outwardly and fulcrumed in the bifurcation of said first arm, a jaw adjustable on the head of the second arm obliquely to said arm, the fulcrum of said second arm being in the line of adjustment of said jaw, and a jaw at the outer end of the first arm for cooperation with said adjustable jaw.

3, In a device of the class described, an arm having a head at its outer end, said head having its outer edge oblique to said arm, a jaw adjustable along said edge, and a second arm' pivoted to the head of the first arm outwardly beyond said edge, said second arm having a jaw cooperable with said first jaw.

In witness whereof, I hereunto subscribe my name this 24th day of November, 1923. 40

LAWRENCE W. ROBINSON. 

